<?php 
/**
 * 图形验证码基类
 * @author dt
 * @time 2017/1/10
 */

use Yii;
use yii\base\Exception;
use app\base\BaseController;

class ValidateCode 
{
    //单例
    private static $instance = null;
    private $charset = 'abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ1023456789';//随机因子
    private $code;//验证码
    private $codelen = 4;//验证码长度
    private $width = 130;//宽度
    private $height = 50;//高度
    private $img;//图形资源句柄
    private $font;//指定的字体
    private $fontsize = 20;//指定字体大小
    private $fontcolor;//指定字体颜色

    //构造方法初始化
    public function __construct() 
    {
        $this->font = dirname(__FILE__).'\sniglet.ttf';//注意字体路径要写对，否则显示不了图片
        // $this->font = dirname(__FILE__).'\symbol.ttf';//注意字体路径要写对，否则显示不了图片
    }

    /**
     * 单例实例化
     * @param array $options
     * @return CurlUtil|null
     */
    public static function getInstance($options = [])
    {
        if (empty(self::$instance)) {
            self::$instance = new self($options);
        }
        return self::$instance;
    }

    //生成随机码
    private function createCode() 
    {
        $_len = strlen($this->charset)-1;
        for ($i=0; $i<$this->codelen; $i++) {
            $this->code .= $this->charset[mt_rand(0, $_len)];
        }
    }

    //生成背景
    private function createBg() 
    {
        $this->img = imagecreatetruecolor($this->width, $this->height);
        $color = imagecolorallocate($this->img, mt_rand(157,255), mt_rand(157,255), mt_rand(157,255));
        imagefilledrectangle($this->img, 0, $this->height, $this->width, 0, $color);
    }

    //生成文字
    private function createFont() 
    {
        $_x = $this->width / $this->codelen;
        for ($i=0; $i<$this->codelen; $i++) {
            $this->fontcolor = imagecolorallocate($this->img, mt_rand(0,156), mt_rand(0,156), mt_rand(0,156));
            // echo $this->fontsize.'--'.$this->fontcolor.'--'.$this->img.'--'.$this->code[$i];exit;
            imagettftext($this->img, $this->fontsize,  mt_rand(-30,30),$_x*$i+mt_rand(1,5), $this->height / 1.4, $this->fontcolor, $this->font, $this->code[$i]);
        }
    }

    //生成线条、雪花
    private function createLine() 
    {
        //线条
        for ($i=0; $i<6; $i++) {
            $color = imagecolorallocate($this->img, mt_rand(0,156), mt_rand(0,156), mt_rand(0,156));
            imageline($this->img, mt_rand(0,$this->width), mt_rand(0,$this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $color);
        }
        //雪花
        for ($i=0; $i<100; $i++) {
            $color = imagecolorallocate($this->img, mt_rand(200,255), mt_rand(200,255), mt_rand(200,255));
            imagestring($this->img, mt_rand(1,5), mt_rand(0, $this->width), mt_rand(0, $this->height), '*', $color);
        }
    }

    //输出
    private function outPut() 
    {
        header('Content-type:image/png');
        imagepng($this->img);
        imagedestroy($this->img);
    }

    //对外生成
    public function doimg() 
    {
        $this->createBg();
        $this->createCode();
        $this->createLine();
        $this->createFont();
        // $this->outPut();
    }

    //获取验证码
    public function getCode($mobile) 
    {   
        $this->doimg();
        $cache = Yii::$app->cache;                  //进行验证码缓存---本次使用YII cache
        $token = BaseController::$token;            //验证码带TOKEN 便于提取验证
        if ($token) {                               //TOKON存在时  在系统内部使用 
            $userId="validate_code".BaseController::$token;
        } else {                                    //TOKON不存在时 外部登录注册使用 
            $userId="validate_code".$mobile;
        }
        $cache->add($userId, $this->code, Yii::$app->params['defaultParams']['code_time_out']);//验证码保存到cache中
        return $this->img;
    }
}
?>